[PATCH 1/1] i2c: ocores: fix polling mode workaround on FU540-C000 SoC
Peter Korsgaard
peter at korsgaard.com
Wed Oct 7 07:40:26 EDT 2020
>>>>> "Sagar" == Sagar Shrikant Kadam <sagar.kadam at sifive.com> writes:
> The FU540-C000 has a broken IRQ and support was added earlier
> so that it will operate in polling mode, but seems to work only
> in case interrupts property is missing from the i2c0 dt-node.
> This should not be the case and the driver should handle polling
> mode with the interrupt property present in i2c0 node of the
> device tree.
> So check if it's the FU540-C000 soc and enable polling mode master
> xfers, as the IRQ for this chip is broken.
> Fixes commit c45d4ba86731 ("i2c: ocores: add polling mode workaround
> for Sifive FU540-C000 SoC")
> Signed-off-by: Sagar Shrikant Kadam <sagar.kadam at sifive.com>
> ---
> drivers/i2c/busses/i2c-ocores.c | 22 +++++++++++++---------
> 1 file changed, 13 insertions(+), 9 deletions(-)
> diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
> index f5fc75b..4405244 100644
> --- a/drivers/i2c/busses/i2c-ocores.c
> +++ b/drivers/i2c/busses/i2c-ocores.c
> @@ -686,17 +686,21 @@ static int ocores_i2c_probe(struct platform_device *pdev)
> init_waitqueue_head(&i2c->wait);
> + /*
> + * Set OCORES_FLAG_BROKEN_IRQ to enable workaround for
> + * FU540-C000 SoC in polling mode.
> + * Since the SoC does have interrupt it's dt has the interrupt
> + * defined but it should be bypassed in driver as this SoC has
> + * a broken IRQ, hence update the master_xfer to use polling
> + * transfers.
> + */
> + match = of_match_node(ocores_i2c_match, pdev->dev.of_node);
> + if (match && (long)match->data == TYPE_SIFIVE_REV0)
> + i2c->flags |= OCORES_FLAG_BROKEN_IRQ;
> +
> irq = platform_get_irq(pdev, 0);
> - if (irq == -ENXIO) {
> + if (i2c->flags == OCORES_FLAG_BROKEN_IRQ || irq == -ENXIO) {
NIT: flags is a bitmask, so i2c->flags & OCORES_FLAG_BROKEN_IRQ would be
better, even if there currently doesn't exist any other flags.
TYPE_SIFIVE_REV0 is also set for two compatibles:
{
.compatible = "sifive,fu540-c000-i2c",
.data = (void *)TYPE_SIFIVE_REV0,
},
{
.compatible = "sifive,i2c0",
.data = (void *)TYPE_SIFIVE_REV0,
},
Are both affected by this issue? if not, we will need to extend the code
to handle them differently.
Other than that, it looks OK to me.
--
Bye, Peter Korsgaard
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